Identification of cytokines involved in hepatic differentiation of mBM-MSCs under liver-injury conditions

AIM: To identify the key cytokines involved in hepatic differentiation of mouse bone marrow mesenchymal stem cells (mBM-MSCs) under liver-injury conditions. METHODS: Abdominal injection of CCl4 was adopted to duplicate a mouse acute liver injury model. Global gene expression analysis was performed to evaluate the potential genes involved in hepatic commitment under liver-injury conditions. The cytokines involved in hepatic differentiation of mBM-MSCs was function-ally examined by depletion experiment using specifi c antibodies, followed by rescue experiment and direct inducing assay. The hepatic differentiation was characterized by the expression of hepatic lineage genes and proteins, as well as functional features. RESULTS: Cytokines potentially participating in hepatic fate commitment under liver-injury conditions were initially measured by microarray. Among the up-regulated genes determined, 18 cytokines known to closely relate to liver growth, repair and development, were selected for further identif ication. The f ibroblast growth factor-4 (FGF-4), hepatocyte growth factor (HGF) and oncostatin M (OSM) were fi nally found to be involved in hepatic differentiation of mBM-MSCs under liver-injury conditions. Hepatic differentiation could be dramatically decreased after removing FGF-4, HGF and OSM from the liver-injury conditioned medium, and could be rescued by supplementing these cytokines. The FGF-4, HGF and OSM play different roles in the hepatic differentiation of mBM-MSCs, in which FGF-4 and HGF are essential for the initiation of hepatic differentiation, while OSM is critical for the maturation of hepatocytes. CONCLUSION: FGF-4, HGF and OSM are the key cytokines involved in the liver-injury conditioned medium for the hepatic differentiation of mBM-MSCs.

EZH2 and STAT6 expression profiles are correlated with colorectal cancer stage and prognosis

AIM: To investigate the role of enhancer of zeste homologue 2 (EZH2) and STAT6 immunohistochemistry in the evaluation of clinical stages and prognosis of colorectal cancer (CRC). METHODS: The expression patterns were examined by immunohistochemistry in both tumor and adjacent non-neoplastic tissues of 119 CRC patients who underwent operation during the time period from 2002 to 2004. RESULTS: The positive rates of EZH2 and STAT6 in CRC cases were 69.7% (83 of 119) and 60.5% (72 of 119), respectively, and there was signifi cant differ-ence when compared with tumor adjacent non-neoplastic tissues (P < 0.05). In all CRC cases, patientswith EZH2-positive, or STAT6-positive expression had lower survival rates than those with EZH2-negative or STAT6-negative expression (P = 0.002 and P = 0.005, respectively). Co-expression of EZH2 and STAT6 showed signifi cantly higher levels in CRC cases of high clinical TNM stages (P = 0.001), and the expression of STAT6 was also correlated with lymph node metastasis and distant metastasis (P = 0.001 and P = 0.016, respectively). Multivariate analysis revealed that EZH2 expression was an independent prognostic indicator of CRC (P = 0.039). CONCLUSION: EZH2 and STAT6 expressions have significant values in distinguishing clinical stages of CRC and predicting the prognosis of the patients.

Oncolytic adenovirus-mediated MDA-7/IL-24 overexpression enhances antitumor activity in hepatocellular carcinoma cell lines

BACKGROUND: Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24) is a novel tumor suppressor gene, which has suppressor activity in a broad spectrum of human cancer cells. We investigated the effect of the replication-competent oncolytic adenovirus SG600-IL24 and replication-incompetent adenovirus Ad.IL-24, both expressing human MDA-7/IL-24 on the hepatocellular carcinoma cell lines HepG2, Hep3B, SMMC-7721, HCCLM3, and the normal liver cell line L02. METHODS: Hepatocellular carcinoma cell lines and the normal liver cell line were infected with SG600-IL24 and Ad.IL-24. The mRNA and protein expression of MDA-7/IL-24 in infected cells was confirmed by RT-PCR, ELISA, and Western blotting. MTT assay was used to investigate the proliferation effect. Hoechst staining and Annexin-V and PI staining were performed to study the MDA-7/IL-24 gene expressed in HCC cell lines and the normal liver cell line. Flow cytometry was used to analyse the cell cycle. RESULTS: RT-PCR, ELISA and Western blotting confirmed that the exogenous MDA-7/IL-24 gene was highly expressed in cells infected with SG600-IL24. MTT and apoptosis detection indicated that SG600-IL24 induced growth suppression, promoted apoptosis, and blocked cancer cell lines in the G2/M phase in hepatocellular carcinoma cell lines but not in the normal liver cell line. CONCLUSIONS: SG600-IL24 selectively induces growth suppression and apoptosis in hepatocellular carcinoma cell lines in vitro but not in the normal liver cell line L02. Compared with Ad.IL-24, SG600-IL24 dramatically enhances antitumor activity in hepatocellular carcinoma cell lines. (Hepatobiliary Pancreat Dis Int 2010; 9:615-621)

Hepatic portal cholangiocarcinoma:a clinical analysis of 70 cases

BACKGROUND: The incidence of hepatic portal cholangiocarcinoma is increasing and it is always associated with poor survival. This study analyzed an effective therapeutic method. METHODS: A retrospective analysis was made on 70 patients with hepatic portal cholangiocarcinoma admitted between January 2004 and February 2007 to the General Hospital of Air Force PLA. RESULTS: Forty-seven patients had hepatic ductjejunum anastomosis after resection of hepatic portal cholangiocarcinorna. Internal or external biliary drainage and canals for internal radiation were performed in those patients unfit for operation. Among the 70 patients, 5 died within 15 months, 27 survived more than 24 months, and the others survived 4-18 months. CONCLUSION: Surgery is the primary therapeutic method for hepatic portal cholangiocarcinoma. Internal or external biliary drainage can prolong the life-span.

Application of the CRISPR-Cas System for Efficient Genome Engineering in Plants

Dear Editor, Recently, engineered endonucleases, such as Zinc-Finger Nucleases （ZFNs） （Carroll, 2011）, Transcription Activator-Like Effector Nucleases （TALENs） （Mahfouz et al., 2011; Li et al., 2012）, and Clustered Regularly Interspaced Short Palindromic Repeats （CRISPR）-associated （Cas） systems （Cong et al., 2013） have been successfully used for gene editing in a variety of species. These systems generate double-strand breaks （DSBs） at target loci to drive site-specific DNA sequence modifica- tions. The modifications include sequence insertion and deletion and other mutations in the host genomes via the error-prone non-homologous end joining （NHEJ） pathway or sequence correction or replacement through the error-free homologous recombination （HR） pathway （Symington and Gautier, 2011）. Here, we show that the CRISPR-Cas system can be applied to generate targeted gene mutations and gene corrections in plants, and the system can also be readily engi- neered to achieve deletion of large DNA fragments and for multiplex gene editing in plants.

Frequent Gain and Loss of Resistance against Tobacco Mosaic Virus in Nicotiana Species

Dear Editor Resistance （R） genes represent one of the most divergent gene families in plants. Novel resistance function might arise through point mutations or sequence exchanges between paralogues （Kuang et al., 2004; Luo et al., 2011, 2012）.